Archive for February, 2010

Tilapia fillets are firm, mild, high in protein, and low in total and saturated fats. Tilapia aquaculture is the world’s third biggest, after carp and salmon. Since you may not be eating carp (it’s mainly a Chinese market), and you may have concerns about eating salmon (mercury contamination, along with the use of fish meal to feed the cultured fish), tilapia may be the way to go when you want to eat fish.

Fresh tilapia fillets (blisstree.com)

There are a bunch of tilapia species, living in fresh, brackish and even salt water, but the most likely farmed species are Nile and Blue. They grow quickly, and to a reasonable size, and they are mainly herbivores, or perhaps opportunistic omnivores. They normally eat algae and detritus, along with the various invertebrates they come across.

They are now raised in fish ponds in many parts of the world, anywhere it’s warm, in what is called ‘extensive’ aquaculture. They are also raised in high density in tanks with recirculating water in ‘intensive’ aquaculture, where they are then fed high-protein pellets that are usually soymeal-based to help them grow more quickly. The tilapia that are produced are heavier than the amount of food pellets they are fed, and the fish are more valuable than the cost of raising them: the culture of the fish is sustainable. You can’t say these things about salmon, cod, tuna or shrimp aquaculture.

Tilapia adults, unfilleted (cichlid.umd.edu)

Is fish meal included in the food pellets? In some commercial products it still is, but it doesn’t need to be, and it shouldn’t be. Even in the remaining cases where it is included, it is a small percentage of the total protein. And new plant protein sources are emerging, for instance peas instead of soybeans.

Tilapia raised in ponds forage mainly on plants like duckweed, which grows unreasonably quickly. In fact, tilapia have been introduced in many places not for food, but to keep duckweed and other aquatic plants under control, and even to keep algae levels low in reservoir water.

Right, I hear you say, but Tilapia doesn’t taste as good a salmon or shrimp. Well, I agree. But these are hard times for our planet, and they are getting harder, and eating tilapia instead of carnivorous fish and shrimp is a positive, helpful act. The fact that you aren’t eating heavy metals such as mercury, along with other contaminants, doesn’t hurt you either. As well, small pelagic herring type fish are not being caught to feed the fish you eat.

Pecan crusted tilapia. Irrestible? (find.myrecipes.com)

For all of these reasons, Seafood Watch, out of Monterrey Bay Aquarium, recommends tilapia farmed in the US as a ‘Best Choice’, and tilapia from Central America as a ‘Good Alternative’. However, it suggests that we still ‘Avoid’ tilapia farmed in China or Taiwan, for the farmers there use a lot of fungicides and bacteriocides to keep their fish healthy, but potentially contaminated, so check out where your tilapia comes from.

Relatively speaking, then, tilapia are a logical food for us to eat instead of farmed salmon or shrimp. And instead of wild caught fish that are endangered or threatened, like many of the tuna species.

Still not convinced? Many chefs say the sauce is all that matters anyway!

The Environmental Performance Index – EPI – for 2010 has just been published. It compares 163 countries, using available data on 25 indicators of environmental health and vitality. Published every two years, this is the third report. Obviously, the data are not quite up-to-date, and the ranks represent us as we were about two years ago. Canada and the US do not fair well, and it is unlikely we have improved in the past two years.

Geothermal power, Blue lagoon, Iceland (virginmedia.com)

Overall, Iceland is #1, European countries make up half of the top 30, and Costa Rica and Cuba join them at #3 and #9. The countries of Sub-Sahara dominate the lowest ranks. Though Canada ranks #46 and the US #61, the pain is in the details. In ecosytem vitality Canada is #140, the US is #142, just ahead of China at #143. Air pollution per capita is a subset of environmental vitality, and the US is #154, China #156, and Canada #158. In climate change, Canada is #140, the US #153….Good grief.

Fishing down the food web. As time passes we eliminate the larger fish, and the marine trophic index drops.

Among the marine related indicators, the US is doing relatively well, certainly a lot better than Canada. Out ot 127 countries that have some marine profile, Canada is #58 in development of marine protected areas, #73 in trawling damage, #125 in fisheries health, and dead last in the marine trophic index, which indicates the extent marine ecosystems have lost their upper predator trophic levels.

Isn’t that something? Canada – rich, educated, developed – has one of the very worst records on the planet as a fishing nation. Here, as with emissions controls, we require some strong top-down leadership. Legislative stale-mates in both the US and in Canada are not an excuse.

So what’s ahead for polar bears? Will they survive and adapt to thinning ice and a warmer climate? Or will they gradually starve and inevitably become extinct over the next half century?

It depends on who you talk to, biologists or Inuit hunters. Two different ways of knowing, two different cultures. Sometimes they agree – in their different ways both have clearly documented that the Arctic is warming rapidly. And sometimes they disagree: Inuit know that polar bears are doing well and increasing in numbers, while biologists know that populations are declining and predict dire times ahead. The US has identified polar bears as ‘endangered’ under the Endangered Species Act.

(whyy.org)

The argument of course is that sea ice is shrinking, along with how long it lasts each spring, and that polar bears depend on sea ice to reach the seals they prey on. The biologists’ data indicate that of the 19 polar bear populations, about half appear to be decreasing, and for most of the rest there are not enough data to call it. Inuit in Nunavut, based on their own observations, think the biologist’s models and simulations are incorrect. They see plenty of healthy polar bears. They want the limited sports hunt to continue, since it brings badly needed funds into the region. Who is ‘right’?

Hunter comforts polar bear that collapsed from heat exhaustion before he could shoot it (ecoenquirer.com)

Traditional ecological knowledge is very different from the data biologists accumulate. TEK is a way of knowing, inseparable from all of the other indigenous knowledge, and inseparable from the spirituality that is at the core of Inuit culture. It is qualitative and holistic, and emerges from the deep combined experience of hunters that stretches back for generations beyond count. TEK cannot just be integrated with biologists’ scientific data, validated where it fits, rejected where it doesn’t. TEK is a process, one that cannot be separated from the people who hold the knowledge.

Are polar bears decreasing in numbers? Certainly there are signs of stress. Even so, the Inuit need to be able to participate in decisions that will influence their lives and their ecosystems. Their way of knowing is different from that of Western science, but it is surely as valid. Decisions made without their participation indicate that their culture still is not respected..

Polar bears adapt. The Inuit know this, and have watched them for thousands of years. Despite huge effort and some successes, Western ecological science also has its limitations. Let’s include other ways of knowing when possible – we’re running out of time.